Dungeons & Dragons Online: Shadow Under Thunderholme (2014)

Explore the dwarven city of Thunderholme and defeat powerful dragons and their allies. This is a premium quest collection with two raids, a large adventure area for hunting monsters and the ability to craft thunder-forged weapons. Part of D&D's 40th anniversary "Tyranny of Dragons" event across multiple products.

Storyline

Thunderholme was a rich, thriving dwarven city, carved from the stone beneath the Thunder Peaks east of Cormyr. One day the dwarves expanded their underground home too far, earning the enmity of Aurgloroasa, an ancient shadow dragon who lived deep beneath the mountains. Aurgloroasa conceived a plan to punish the insolent dwarves for intruding into her realm. Aurgloroasa whispered to Dagan, Thunderholm's regent, corrupting his soul over a period of many years. She persuaded Dagan to build a great temple in Thunderholme. The people of Thunderholme thought this temple would be dedicated to Dumathoin, the god of mining. Yet at the opening ceremony, Dagan summoned Aurgloroasa instead. The shadow dragon slew the city's inhabitants - including Dagan - and claimed Thunderholme as her own. Many years later, Aurgloroasa still reigns supreme in Thunderholme. To consolidate her power, she raised the slain dwarves to be her skeletal servants. She formed an alliance with a mated pair of red dragons. She also had herself transformed into a dracolich, gaining countless fanatical followers from the Cult of the Dragon in nearby Sembia. Now she spends her days planning to expand her power even further - and her plans have recently taken a disturbing, unexpected turn.